Rebuilding the RB25det - Machine shop

Table of Contents

Machine shop

The RB25 was pretty much disassembled when it arrived. A couple weeks after, it was put in the machine shop. 

This is when we started to formulate the list. Marco wanted to do it step by step. 

  1. Wanted to make sure the block was good.
  2. Get parts needed for the machine shop.
  3. Then order the parts that he needed to start the build. 

The machine shop cleaned and checked the block. When they found out the #6 was bad, the whole block was honed. The heads were taken apart and found to have no issues. 

Nitto Crank Collar

One of the issues people have posted about were the oil pump contact with the crank snout and that it is very minimal contact. Once they contact wears out, it leads to oil pump failure. 

One of the best things to do is a spline gear, but at the time, Supertec made them and they were $1000 for it… and just couldn’t justify the cost. 

I did go with the minimal upgrade though, the extended crank collar. 

RB25det head

The head was disassembled, hot tanked and assembled 

  • OEM valve stem seals
  • Tomei valve guides
  • Tomie valve springs type A
  • Supertec valves #NIVN-1052-12
  • Franklin Performance head drain